In a modest ceremony in Beijing in April 2003, a small bottle of water was presented to the city’s vice-mayor, Niu Youcheng. To an outsider it didn’t seem like much-a variant on some ancient Chinese tea ceremony, perhaps. But its significance for the future of a city of 14 million people, the capital of the world’s largest country, could be profound.

The water had come from the Danjiangkou Reservoir, a huge man-made expanse of water more than 1,000 km to the south on a tributary of the Yangtze River, the world’s fourth-largest river. Its arrival in Beijing symbolized the start of what China is calling the biggest engineering project ever undertaken anywhere on the planet. It is a scheme to divert part of the flow of the Yangtze, which drains most of southern China, to replenish the parched north, where rising demand for water for farms and cities is emptying the Yellow River and where underground waters on which cities like Beijing increasingly rely are being pumped dry.

The first Yangtze water should be flowing north along a canal from Danjiangkou in time for Beijing to fill swimming pools and festoon its stadiums with fountains during the Olympic Games, which it is scheduled to host in 2008. The canal will be 60 m wide and as long as France, crossing 219 rivers, 500 roads, and 120 railway lines as it takes some 12 km3 of water a year across the crowded plains en route to Beijing.

But this is just one of three links planned to bring water from the Yangtze to the great cities and wheat fields of northern China. It will be complemented by two other equally large and complex diversions, one to the east and another far to the west in Tibet. By the time all three stages of what China calls the south-north diversion are completed in about 20 years, the project will siphon northward about 50 km3 of water a year. That is less than one-tenth of the Yangtze’s typical annual flow but is almost equivalent to the current flow of the Yellow River in its middle reaches and nearly three times what the Yellow River discharges into the sea in a typical year.

This is big engineering. Chinese engineers are still imbued with a sense of optimism about their ability to remake the landscape-an optimism that has largely been lost in the West. They are attempting nothing less than the re-plumbing of their nation by remaking two of the world’s greatest rivers.

The south-to-north project follows hot on the heels of the Three Gorges Dam, whose reservoir is already being filled on the Yangtze. Three Gorges will be the world’s largest hydroelectric dam and will create a lake some 400 km long. But it suddenly seems like a warm-up act for the main event, each of whose three stages will match Three Gorges for size and cost. It is as if the U.S. had decided to dam the Mississippi at Minneapolis, at St. Louis, and again at Memphis and to pipe its waters into the Rockies to refill the Colorado. The implications are immense.

Until now, the world has for the most part built its cities where the water is-close to big rivers. Even modern superdams like the Hoover Dam on the Colorado River, the Aswan Dam on the Nile, and the Soviet-built monstrosities perched in the quake-infested mountains of Central Asia usually do little more than control the flow of their rivers. They catch seasonal floods in the mountains and release them downstream in the dry season, or they divert water to irrigate the plains of the river’s own basin. But China’s south-north project is something different. It aims to move water on a huge scale to where the people are. Indeed, to where several hundred million people are.

While China may be the first to act on such a scale, it is not alone in harboring such plans. National and international re-plumbing is the new vogue among engineers for whom mere dam building has become pass?. A rash of similar megaprojects-the pipe dreams of engineers and geopoliticians around the world for many years-is on the verge of being turned into reality. Serious plans and serious funding are

being assembled for schemes on the parched plains of India, in the Western Desert of Egypt, and, maybe soon, in the Australian outback, in the jungles of central Africa, and amid the icy torrents of northern Canada. All aim to cut civilizations loose from their geography, to bring water long-distance to where the people are-or where their leaders wish them to be.

Is all this mega-engineering the inevitable future? Will the twenty-first century be the era of national water grids and planetary re-plumbing in the way that the twentieth century became the era of blockading rivers with dams?

Many believe that the heyday of giant water projects is over, that they can no longer deliver on their promises-and that megaengineering is part of the problem rather than part of the solution. Environmentalists point out that diverting river waters away from their basins and into entirely new and often distant catchments will create a whole new suite of problems. Dams are already largely responsible for dramatic declines in the world’s freshwater fisheries, but transfers between basins will further destabilize ecosystems and shift predator species and diseases from one river system to another. Many point to the appalling ecological havoc in Central Asia when Russian engineers diverted most of the flows of two giant rivers away from the Aral Sea. The sea has dried up, turning the surrounding area into a salt-encrusted and toxic wilderness.

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So before we start writing the billion-dollar checks, it’s worth considering whether there is another cheaper and better way. The need now, according to Peter Gleick of the Pacific Institute for Studies in Development, Environment, and Security, is for “a soft path” that complements centralized physical infrastructure with lower-cost community-scale systems. People like Gleick argue that we have got the nature of our current water crisis all wrong.

We are not running out of water. What we face is a crisis about how we use and manage water. We do not have a supply-side problem so much as a demand-side problem. The bottom line is that we manage water so badly that the potential for doing it better is vast. The solution in most cases is not more and bigger engineering schemes. We have to treat nature as the ultimate provider of water rather than a wasteful withholder of water. We must learn to “ride the water cycle.”

There are really two “soft” solutions. The first is to devise new ways of collecting water locally. In many arid regions there is ample rain, but it all falls during a few stormy days and rapidly runs off the land into rivers and the sea. In monsoon lands such as India, all the rain falls in about 100 hours a year. In many coastal regions, there is little rain but huge amounts of moisture in fogs.

What is needed in such places is a revival of local systems for collecting water: either storing it in tanks or allowing it to percolate into the soil, from where it can be pumped later. And people are starting to do this. In India, scientists and swamis, schoolteachers and policemen are not waiting for promised giant dams and river links to provide water; they are mobilizing communities to catch the monsoon rain. Palestinians on the West Bank, Tunisian olive farmers, and Egyptian bedouin are all finding that catching the rain today is better than waiting for giant mega-projects tomorrow. From China to Algeria, farmers are reviving ancient tunnels dug beneath the earth to bring underground water to the surface. And from Chile to Namibia, they are using innovative technologies like catching the moisture in fogs to keep the taps flowing.

The second “soft” solution is to make more sensible use of the water that has been collected. In the U.S., the amount of water used to flush the nation’s toilets has been cut by three-quarters in the past two decades, thanks to fairly modest alterations to valves and redesigns to the shape of the toilet bowl. One British water company found that modifying every toilet in London would save more water and be cheaper than building a new reservoir on the River Thames.

The biggest savings can undoubtedly be made in agriculture. At present, only about one percent of the world’s irrigated farms use water-saving technologies such as distributing water through perforated hoses and recycling waste water. Even in a severely water-stressed country like China, the figure is only three percent. As a result, by a conservative estimate, two-thirds of the water sent down irrigation canals never reaches the plants it is intended for. Yet Israel has used drip irrigation to increase farm output fivefold in the past 30 years without increasing water use. Drip irrigation need not be expensive. In India, everything from old bicycle inner tubes to rolls of cheap, mass-produced, polyethylene popsicle containers has been recycled to create tubing for drip irrigation.

Farmers can make more savings by leveling land so water does not pond up, by planting on raised beds, and by plowing less. And there is plenty to be done at plant-breeding stations. Most modern “high-yielding” plant varieties of rice, wheat, and other staples may make efficient use of land, but they are water guzzlers. Only now are breeders turning their attention to varieties that use water well.

There are similar opportunities in water supply systems. Evaporation from the surfaces of reservoirs in the tropics can remove up to one-third of their water. Yet in trials on small reservoirs and canals, evaporation can be cut by one-third simply by pouring onto the water surface an ultra-thin polymer solution developed by a company in Canada. There are still technical problems. On larger reservoirs, the wind breaks up the polymer layer, and nobody is sure about the ecological effects of cutting off the exchange of gases with the atmosphere. But in theory at least, this could one day save millions of cubic meters of water in reservoirs from the Colorado to the Nile.

Meanwhile, in cities from London to Nairobi, between one-third and one-half of all water put into the mains disappears through leaks before reaching customers. Yet cities with active programs to find and repair leaks have found saving water is cost-effective. Singapore has got its leaks down to five percent.

If we take the trouble to use the water-saving technologies available, we can save water in the way we are learning to save energy and recycle waste-for the good of our planet as well as our pockets. And were we to adopt such an ethic, we would increasingly look for local solutions to our problems rather than attempt to re-plumb the planet. It remains to be seen whether we will be able to do so.

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In the middle of April 2004, something odd happened. Chinese Premier Wen Jiabao called a temporary halt to work on a giant new hydroelectric dam that would drown an area described as China’s Grand Canyon. The canyon is on the Nu River, which, after it passes south into Burma and Thailand, is known to the rest of the world as the Salween. The premier’s postponement of engineering work while new studies of potential adverse impacts were conducted was a reprieve for one of China’s last wild rivers. Was it a change of heart from the country that houses half the world’s large dams? Could be. Such projects “cause great concern in society,” said the premier, the successor to the notorious dam enthusiast Li Peng, who pushed forward both the Three Gorges Dam and the south-north river transfer scheme.

The premier’s statement did seem to be part of a pattern. It came only weeks after China’s State Council Energy Research Center called for a new emphasis on reducing demand for electricity rather than on building ever more hydroelectric dams-and only days after China’s State Environmental Protection Administration had announced plans for drastic increases in water prices to curb demand.

Nobody was talking of calling off the south-north project. But the myth that all the country’s water problems would be solved once the Yangtze water was flowing into the Yellow River seemed to have been broken. We shall see what happens in practice. But as I write these stories, I have received an email from an Indian architect who spent two months in China learning about the country’s huge new investments in rainwater harvesting in the province of Gansu. Here, villagers have revived the ancient tradition of catching rain and storing it in underground cellars. More than 2 million concrete water cellars were boosting farm yields across a wide area of near-desert close to the Yellow River. “I am very excited about the prospects for cooperation between India and China on this,” he wrote. The new thinking, the “soft engineering,” was starting to happen on a scale that really made a difference.

HARVESTING THE RAIN

Haradevsinh Hadeja is a cricket-playing former Indian police officer and, so far as his fellow villagers in the backwoods of the Indian state of Gujarat are concerned, a near-magical diviner of water. He has remade his village so that it can capture and keep the monsoon rains and fill taps, irrigate crops, and even beautify the village with trees and ponds. Just off the main road to the town of Rajkot, where Mahatma Gandhi went to school, the village of Rajsamadhiya is a revelation in this parched landscape of dying rivers, empty wells, occasional visits from emergency water tankers, and the long, long wait for water promised from a dam on the Narmada river at the other end of the state.

Hadeja’s is no overnight success. He began work 25 years ago, trying to catch the rain. “I am an uneducated person. I saw that people were leaving the village, and I wanted to develop the village so they could stay. That meant growing more crops, which meant finding more water,” he told me as we toured the village. He had noticed how many villages in the area still had traditions of collecting water in ponds that kept going through the nine-month dry season. They provided a little water for cattle and an emergency source of water for the villages. He simply developed that idea, he says. He surveyed the land in his own village and found eight low-lying areas into which the monsoon rain naturally flowed. “We decided to channel more water into those low areas. We built dikes to channel the flow and small dams to keep the water once it arrived.”

He found that much of the water in the new ponds soon disappeared below ground into the sandy soil. Disaster? It turned out not. For this water did not travel far. And it soon began to fill the village’s wells. While other villages were finding their wells going dry, in Rajsamadhiya the water table was rising and dried-up wells were returning to life.

Word spread about his endeavors. “After 1994, I began to meet scientists who came here to see what we were doing and to offer their own expertise,” he says. One group of scientists turned up with satellite images of the village that helped him refine the drainage system. He identified hidden cracks below the village that drained rainwater away before it had a chance to fill wells and nourish the soil. By plugging them with concrete, he kept more water for the village. Today, the water table under the village is just 6 m from the surface, compared with 30 m in most of the surrounding villages.

STOPPING THE FLOW

Bill Hereford, a worker for the aid agency Oxfam, stumbled upon the late Michael Evenari’s desert farm while on sabbatical from his work in West Africa. In the 1970s Evenari, an archaeologist from Hebrew University in Jerusalem, had excavated and renovated ancient farms in Israel’s Negev Desert. Reviving the dying art of rainwater harvesting, Evenari discovered that even in the midst of drought, he could keep the fields damp. In fact, he was able to grow most of the crops mentioned in the Bible.

The miracle was achieved by six lines of stone walls, each about 45 cm high, winding from a nearby hill to the farm. The walls captured the occasional flash floods high on the slopes and brought the water down to the fields below.

Hereford wondered, if it could be done in the Negev Desert, then why not in the drought-torn West African state of Burkina Faso, where he worked? Upon returning to Africa, he encouraged farmers to collect the large number of stones that littered the landscape and to use them to make low stone walls along the contour lines of the hillsides. The stones would both stop the occasional heavy rains from washing away the soils and hold onto the water long enough for it to penetrate the soil and reach the roots of plants.

The first farmer to try was Jean-Marie in Kalaska village. It was the notorious drought of 1983. He had nothing to lose. The field where he laid the stones had not produced a crop for a decade. Jean-Marie told Oxfam writer Paul Harrison: “Everybody laughed at me at first. They said it was useless. I was wasting my time. But when they saw the millet, they stopped laughing and started building lines too.”

Soon collective memory kicked in. The idea was not quite as novel as everyone, including Hereford, had thought. Village elders recalled that stone walls were an old local technique for capturing rainfall. Soon the entire village was building long, snaking walls across the fields, and crop yields were up 50 percent. Neighboring villages took up the idea. Oxfam began to develop a training program to bring people from across the country to learn from the villagers of Kalaska. By the late 1980s, there were walls in more than 400 villages catching water for farming on some 8,000 ha. Oxfam stopped counting. Its efforts were no longer needed to spread the technology. In fact, the main limitation on its spread was the supply of stones. Oxfam’s last investment was a dump truck to help farmers collect them.

CATCHING THE FOG

It looked like a giant washing line: 75 large sheets of plastic mesh suspended along a remote hilltop, known as the El Tofo ridge, in the Atacama desert of northern Chile. It does not rain here for years on end. But rather than being hung out to dry, these plastic sheets are getting wet by capturing the moisture of fogs that regularly roll in off the Pacific Ocean. It is the first new method of providing drinking water in over a century.

The project provided 18,000 liters of water a day for Chungungo, a small town that had previously depended on tankers driven from 80 km away. “Until we set up the water system, the town was dying,” says Bob Schemenauer, who masterminded the project for Environment Canada, a government agency, and then spun off his own organization, FogQuest, to develop it.

The giant sheets, each measuring 12 m by 3 m, faced into the wind high above the village. Tiny fog droplets accumulated on the mesh until they formed single large drops that ran down into a trough that flowed to the town. Every square kilometer of sheeting harvested almost 7 liters of water a day-2,500 liters in a year.

“With a secure water supply, people began to return [to the town] and new houses were built,” says Schemenauer. Yet ironically, the system is now defunct, the plastic sheets torn and abandoned. According to Schemenauer, the town grew so much that the government decided to install a water pipeline at a cost of US$1 million to help it grow more. Although there was still plenty of room on the hill for more sheets, neither the local authority nor the townspeople took the trouble to maintain the existing system after Schemenauer left at the end of the 1990s.

Schemenauer is developing the fog-harvesting system for other arid lands that receive fogs but little rain, from the Caribbean to Namibia to Yemen. In Oman, where there are fogs 80 days a year, Schemenauer says his sheets got ten times the yield they did in Chile. The new technology works. But in Chile at least, the social organization for handling a communal resource is thus far lacking.